1. Field of the Invention
The present invention relates to the field of electrical connectors.
2. Prior Art
The preferred embodiments of the present invention are used as connectors between backplanes and modules mounted on the backplanes, and accordingly the prior art relating to such connectors will be discussed. However it is to be understood that use of the present invention is not so limited, and the invention may be adapted for as wide range of use.
Electrical connectors of various sizes and configurations are well known in the art. Multiple pin connectors usually use a multiple pin male connector member that plugs into a female receptacle, with the electrical connections depending on direct metal to metal contact to complete the circuits. For most applications, connectors of this type are satisfactory, though can cause connection failures on initial installation by pin bending on the male connector, or over a period of time as dirt and corrosion build up.
For high reliability applications and in harsh environments, such as for under water use, high humidity and dusty or dirty environments, typically the connector housings are round and include an alignment feature plus a rotary collar on one connector member that screws onto the other connector member to maintain positive engagement of the connector members, with an O-ring providing the ultimate seal of the pins and sockets in the connector.
However, in some instances, physical constraints and other considerations prevent the use of such an O-ring sealed connector. One such application of connectors is in backplane applications wherein a relatively large number of boards or modules must be “plugged” into a backplane, typically side by side with very little space between them. In that regard, as used herein, unless the context indicates otherwise, a backplane is a printed circuit board into which boards or modules are “plugged”, which backplane printed circuit board provides power to and/or communication with the module or printed circuit mounted on the backplane printed circuit board, or the entire assembly that includes such a backplane printed circuit board.
A simple edge connector is adequate for applications wherein one can be assured that the environment will not be hostile. For applications that require high reliability and lack of a harsh environment cannot be assured, such as in industrial process control applications, circuit failure detection techniques and/or error detection and correction techniques are commonly used, as is redundancy in circuitry to provide high reliability in circuit operation over long periods of time. However, corrosion is a persistent problem and may render an initially good contact nonfunctional, as such assemblies may sit almost indefinitely without attention until a failure does occur. Therefore conventional connectors remain a weak link in the overall system.